The possibility of dyeing polyamide fabric with a substantive dye is studied in this paper. This type of dye most often dyes natural fibers, e.g. cotton, while polyamide belongs to the group of synthetic fibers. Due to their outstanding mechanical properties, polyamide fibers are used in the production of clothing, technical textiles and reinforcement of textile composites. Dyeing by substantive dye is performed with the aim of applying it in industrial conditions. Substantive dye can be bonded by hydrogen bridges with amide groups in a polyamide chain. 100 % polyamide 6.6 fabric was used. The samples were dyed at temperatures of 95 °C with the addition of acetic acid. Samples were dyed at a time interval of 5, 10, 20, 40, 50, and 60 minutes. The solution contained dye concentrations of 5, 10, 15, 20, 25 and 30 mg/dm3. From the results, the degree of dye exhaustion and adsorption capacity were analyzed. At the highest applied dye concentrations and the longest dying time, the highest adsorption occurs. Increasing the concentration of dye when dyeing PA 6.6 fabric with a substantive dye reduces the degree of exhaustion, longer dyeing gives a higher degree of dye exhaustion, and this is maintained throughout the dyeing process. The adsorption capacity increases during the increase of the initial dye concentration and time, i.e. a larger amount of dye or a longer period of dyeing yield a higher amount of adsorbed dye per unit mass of polyamide fabric.
Polyamide, Dyeing, Adsorption, Substantive dye